Re: [PATCH v2 2/2] bisect: output bisect setup status in bisect log

[Chris Down <chris@chrisdown.name>]

Taylor Blau writes:
>On Fri, May 06, 2022 at 01:52:54AM +0100, Chris Down wrote:
>> This allows seeing the current intermediate status without adding a new
>> good or bad commit:
>>
>>     $ git bisect log | tail -1
>>     # status: waiting for bad commit, 1 good commit known
>
>Hmm. I was worried that this would make it harder to turn the output of
>"git bisect log" into something you can inject into "git bisect replay
><log>". But it doesn't, because you prefix the status lines with a '#'
>character.
>
>That's good, and I think it's an improvement over what I'd currently
>recommend, which would be something like:
>
>    git bisect log | grep '^# bad:'
>    git bisect log | grep '^# good:'
>
>to see the state of our good and bad endpoints.

>
>I'm not totally convinced it _needs_ to live in "git bisect log",
>though, since it feels like additional information that is just added
>for convenience. That's not the worst thing in the world, but I think
>it would be fine to just take the first patch (with my suggestions
>applied) as well.

There was some discussion in the v1 thread (Message-ID: 
<xmqqv8uo1mk6.fsf@gitster.g>) about adding an additional `git bisect 
status' command, but while writing it my immediate thoughts were that it 
doesn't make much sense to separate from the rest of the log. I'm curious what 
Junio's thoughts are on that, happy to do it whichever way is preferred. :-)

>> Signed-off-by: Chris Down <chris@chrisdown.name>
>> ---
>>  builtin/bisect--helper.c    | 25 ++++++++++++++++++++-----
>>  t/t6030-bisect-porcelain.sh |  9 +++++++--
>>  2 files changed, 27 insertions(+), 7 deletions(-)
>>
>> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
>> index 9d583f651c..ef75f0a0ce 100644
>> --- a/builtin/bisect--helper.c
>> +++ b/builtin/bisect--helper.c
>> @@ -404,6 +404,21 @@ static struct bisect_state bisect_status(const struct bisect_terms *terms)
>>  	return bs;
>>  }
>>
>> +__attribute__((format (printf, 1, 2)))
>> +static void bisect_log_printf(const char *fmt, ...)
>> +{
>> +	va_list ap;
>> +	char buf[1024];
>> +
>> +	va_start(ap, fmt);
>> +	if (vsnprintf(buf, sizeof(buf), fmt, ap) < 0)
>> +		*buf = '\0';
>> +	va_end(ap);
>> +
>> +	printf("%s", buf);
>> +	append_to_file(git_path_bisect_log(), "# %s", buf);
>> +}
>
>This direct use of vsnprintf might be avoided by preparing the output in
>bisect_print_status() via a strbuf and then calling:
>
>    append_to_file(git_path_bisect_log(), "# %s", buf.buf).

I'm not intimately familiar with the codebase, so maybe I'm missing something, 
but isn't it overkill to use a string buffer for something which is isn't going 
to then be used as a mutable buffer?

Happy to do it whichever way works for you folks, but would be good to 
understand the rationale so that I can write better patches next time :-)

>>  static void bisect_print_status(const struct bisect_terms *terms)
>>  {
>>  	const struct bisect_state bs = bisect_status(terms);
>> @@ -413,13 +428,13 @@ static void bisect_print_status(const struct bisect_terms *terms)
>>  		return;
>>
>>  	if (!bs.nr_good && !bs.nr_bad)
>> -		printf(_("status: waiting for both good and bad commits\n"));
>> +		bisect_log_printf(_("status: waiting for both good and bad commits\n"));
>>  	else if (bs.nr_good)
>> -		printf(Q_("status: waiting for bad commit, %d good commit known\n",
>> -			  "status: waiting for bad commit, %d good commits known\n",
>> -			  bs.nr_good), bs.nr_good);
>> +		bisect_log_printf(Q_("status: waiting for bad commit, %d good commit known\n",
>> +				     "status: waiting for bad commit, %d good commits known\n",
>> +				     bs.nr_good), bs.nr_good);
>>  	else
>> -		printf(_("status: waiting for good commit(s), bad commit known\n"));
>> +		bisect_log_printf(_("status: waiting for good commit(s), bad commit known\n"));
>>  }
>
>Interesting; this patch removes the output that we were giving to users
>in the last patch. Should it go to both places?

Not sure I understand, we printf() in bisect_log_printf, no?